Swatipriyanka Sen

Evaluation of paraprobiotic applicability of Lactobacillus plantarum in improving the immune response and disease protection in giant freshwater prawn, Macrobrachium rosenbergii (de Man, 1879)

Paraprobiotics, also known as ghost probiotics, are non-viable microbial cells which, when administered in adequate amounts, confer a benefit on the host. However, the advantage of non-viable microbes over their viable counterparts is a much debated topic in aquaculture. Therefore, the present study was conducted to evaluate paraprobiotic effect of heat-killed Lactobacillus plantarum on giant freshwater prawn Macrobrachium rosenbergii. A 90-day feeding trial was conducted by feeding prawn juveniles (mean weight ± SE: 0.54 ± 0.03 g) with three experimental diets prepared by supplementing basal diet (Crude protein: 38%; Gross energy: 387 kcal 100 g(-1)) with different concentrations of heat-killed probiotics bacteria viz. HKPB1 (10(7) cfu g(-1) diet), HKPB2 (10(8) cfu g(-1) diet), HKPB3 (10(9) cfu g(-1) diet) and control diet (unsupplemented diet). In the present study, growth parameters viz. WG % and SGR and feed utilization parameters viz. FCE, FCR and PER, though improved marginally in all experimental groups, were found to be insignificant (P > 0.05) compared to the control. The immune parameters viz. total hemocyte count (THC), phenol oxidase (PO) activity, respiratory burst (RB) activity and clearance efficiency were significantly improved (P < 0.05) with concurrent decrease (P < 0.05) in cumulative mortality against Aeromonas hydrophila challenge in all the experimental groups except for HKPB1, where PO and RB activity did not improve significantly (P > 0.05) compared to the control. Among the experimental groups, though the improvement in immune parameters was higher (P < 0.05) in HKPB2 and HKPB3 compared to HKPB1 and the control, no significant difference (P > 0.05) was observed between HKPB2 and HKPB3. The results obtained from the present study indicate that the application of heat-killed L. plantarum at a concentration of 10(8) cfu g(-1) diet, though not effective in augmenting the growth and feed utilization parameters, can significantly improve immune parameters and disease resistance of M. rosenbergii in the laboratory condition.

First record of blue-spotted stingray, Neotrygon kuhlii from Gujarat, north-west coast of India

One female specimen of blue-spotted stingray, Neotrygon kuhlii was collected from a single day trawl catch along with other species of rays from the Saurashtra coast of Gujarat, India. The present paper describes the first record of the blue-spotted stingray from the State of Gujarat, thereby adding another species to the total recorded species list from the area.

First Record of Stanaland’s Sole (Solea stanalandi, Randall & McCarthy) 1989 from Indian Waters

A single specimen of the Stanaland’s sole, Solea stanalandi was caught by a commercial trawl from Gujarat coast and landed in Mangrol fish landing centre on 23rd January, 2017. The species is presently considered as one of the data deficient species by the International Union for Conservation of Nature (IUCN) due to the dearth of crucial information on the ecology, distribution and population characteristics of the species. Hitherto, the species was believed to be endemic in Persian Gulf alone. This is the first report of its occurrence from Indian waters, describing the extension of its geographical distribution within the Indian water. The fish was examined for its morphometrics and meristic characters and described. The new report of S. stanalandi in Indian fisheries could provide a novel avenue for generating vital baseline information to understand the ecological significance of the species in the region.